Logic Masters Deutschland e.V.

This puzzle was made to celebrate Flinty's birthday!
Flinty invented the Dutch Flat Mates constraint, and we often collaborate on puzzles for his Flat Mates series. In this puzzle, I used two of the constraints we worked with over the past year.
Happy Birthday, Flinty!

To solve online, click here or on the image below.

Rules

Normal Sudoku rules. place the digits 1-9 so that they do not repeat in any row, column, or 3x3 box.

Dutch Flats: Every 5 in the grid must have a '1' directly above it or a '9' directly below it. It may have both, but it doesn't need both.

Clues outside the grid are both Numbered Rooms and Easy as ABC clues.

Numbered Rooms: Clues outside the grid indicate the digit which has to be placed in the Nth cell in the corresponding direction, where N is the digit placed in the first cell in that direction.

Easy as ABC: Clues outside the grid indicate which digit of that modular set is seen first in the respective row or column. {1,4,7}, {2,5,8}, or {3,6,9}.

Liars and Killers: Not all killer clues are accurate, but the digits in a cage must sum to AT LEAST the clue in the top left corner. Digits may not repeat within a cage.